The Internet Engineering Task Force (IETF) initiated the development of the E.164 Number Mapping (ENUM) system for facilitating the interconnection of communications networks that rely on telephone numbers with the communications networks that utilize the Domain Name System (DNS). In particular, the ENUM system can map a particular number referred to as an E.164 number to one or more Uniform Resource Identifiers (URIs) in the DNS. URIs are strings of characters that identify resources such as documents, images, files, databases, e-mail addresses, websites or other resources or services in a common structured format. A URI can include a SIP URI, an instant messaging (IM) identifier, an e-mail address identifier, an Internet chat session identifier, or an IP address.
FIG. 1 is an exemplary communications network, generally designated 100, utilizing the ENUM system. Network 100 includes a signaling point (SP) 102 (e.g., a gateway, switching point, etc.) for connecting the Public Switched Telephone Network (PSTN) system 104 to an IP Multimedia Subsystem (IMS) 106. SP 102 is operable to enable communication between a conventional telephone unit or another suitable network device connected to PSTN 104 and a packet telephone unit or another suitable network device connected to IMS 106. The mobile telephone unit can communicate to IMS 106 via session initiation protocol (SIP) proxy server 108. The conventional telephone unit and packet telephone unit can communicate voice data, text data, or other suitable data. ENUM system can be utilized, for example, when a user of the standard telephone unit attempts to reach a subscriber associated with the packet telephone unit.
Communication between the conventional telephone unit and the packet telephone unit can be initiated when a user of the conventional telephone unit dials an E.164 formatted called party number (referred to herein as an E.164 number) for reaching a subscriber associated with the packet telephone unit. The dialed E.164 number (or called party number) is communicated from the conventional telephone unit to PSTN 104. PSTN 104 can then generate an ISUP IAM message 110 containing the E.164 number and send IAM message 110 to SP 102. In this example, SP 102 determines that the called subscriber phone is a packet phone and that an ENUM query is required. SP 102 formulates an EN UM query 112 and sends the query to EN UM database 114. In the ENUM query, the E.164 number is converted to ENUM message format by reversing the digit order of the dialed E.164 number and appending the highest level domain e164.arpa to the end. For example, if the original E.164 number is 123-456-7890, ENUM query 112 is converted 0.9.8.7.6.5.4.3.2.1.e164.arpa (also referred to herein as an E.164 number). ENUM server 114 uses the ENUM query to retrieve one or more naming authority pointer (NAPTR) records associated with the E.164 number. Each of the NAPTR records may identify at least one URI corresponding to the subscriber with the E.164 number. The URI may identify the mobile telephone unit. The URI is then communicated to SP 102 in an ENUM response 116 for establishing communication between the conventional telephone unit and the packet telephone unit.
In addition, more than one URI can be contained in the NAPTR records for identifying one or more other network devices, services and/or addresses. For example, another URI returned to SP 102 can identify a different way of reaching the subscriber associated with the dialed E.164 number, such as via e-mail or paging.
Rather than simply returning the URI or set of URIs obtained from ENUM server 114 to SP 102, it may be desirable to obtain additional information, such as the Quality of Service (QoS) information associated with each of the obtained URIs that may be used to contact the called party. Examples of QoS information may include the sound quality and the amount of throughput or bandwidth that is available to each URI. Current mechanisms for obtaining ENUM and QoS data are distinct. For example, ENUM data is obtained using ENUM queries and QoS data may be obtained or provided by a node, such as an end office switch or HLR serving a subscriber. In addition, QoS data is not linked to ENUM data. Rather, QoS data may be stored for conventional subscriber identifiers, such as subscriber directory numbers.
As described above, the mechanisms for obtaining ENUM and QoS data are separate and distinct. However, it may be desirable to combine QoS information with ENUM information in order to obtain enhanced contact information for a subscriber with multiple ENUM identities. Currently, such a combined mechanism does not exist.
Accordingly, in light of these difficulties associated with conventional ENUM systems, there exists a need for improved methods, systems, and computer program products for providing a combination of ENUM and QoS services in a communications network.